Residents of San Francisco Bay have been playing a singular game this week: a twitter-fueled scavengers hunt that take them across town looking for envelopes full of cash.

An anonnymous philantrophist has been hiding envelopes with up to $100 dollars in public places –such as the beach, an excavator and fire hydrants- and dropping hints for people to find the money through a Twitter account (@HiddenCash) which already has over 250,000 followers.

The hunt is described as an “An anonymous social experiment for good”, and it seems to have achieved its goal. “How great to see people having so much fun. @HiddenCash leads the way by putting a smile on faces. Kudos, #KeepOnSpreadingCheer,” twitted Angie S. (@angels510)

The anonymous, a real estate investor according to CNN talked to the network keeping his identity in secret. "This is not a set-up charity, but I wanted to do something fun and creative," he said, and stressed that he plans to continue with the hunt “indefinitely”.

"I'd like for this to become a movement," he was quote as saying."If you can give back, it's at least as rewarding as making good investments and getting big checks and making a lot of money."

“I'm running around leaving money in different places, and there's only one me," the man explained adding that a friend is helping.

The envelopes were first dropped in San Francisco but the experiment quickly spread to Oakland, San José and Los Angeles, its latest stop, where the philantrophist plans to give away $1,000 today.